SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8adfde76ee32c2a0235099cc1b34cdde3747d6f3d0cc9956b5526a68ee29932' 
  AND token = 'omiGRurh1ckDU70nqJeoqaaBGUE01B5Bya9uWpYBbh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}